Functional liver-image guided hepatic therapy (FLIGHT): A technique to maximize hepatic functional reserve
This study dosimetrically compares functional liver image-guided hepatic therapy (FLIGHT) to standard stereotactic body radiation therapy (SBRT) plans. In the FLIGHT plans, functional data from hepatobiliary iminodiacetic acid (HIDA) single photon emission computed tomography (SPECT) scans serve as a road map to guide beam arrangement. While meeting the same target volume coverage, plans are optimized to reduce dose to high-functioning liver. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 19, 2019 Category: Radiology Authors: Yukie Furukawa, David E. Long, Susannah G. Ellsworth Source Type: research

Effect of collimator angle on HyperArc stereotactic radiosurgery planning for single and multiple brain metastases
We assessed the effect of collimator angle on the dosimetric parameters for targets and organs at risk (OARs) for collimator-optimized HA (CO-HA) and non-CO-HA (nCO-HA) plans. The nCO-HA and CO-HA plans were retrospectively generated for 26 patients (1 to 8 brain metastases). The dosimetric parameters for planning target volume (homogeneity index [HI]; conformity index [CI]; gradient index [GI]) and for OARs were compared. The modulation complexity score for volumetric modulated arc therapy (MCSV) and monitor units (MUs) were calculated. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 2, 2019 Category: Radiology Authors: Shingo Ohira, Tomohiro Sagawa, Yoshihiro Ueda, Shoki Inui, Akira Masaoka, Yuichi Akino, Hirokazu Mizuno, Masayoshi Miyazaki, Masahiko Koizumi, Teruki Teshima Source Type: research

Dosimetric comparison of two treatment planning systems for spine SBRT
Two commonly used treatment planning systems (TPS) are compared for the planning of spine stereotactic body radiotherapy (SBRT). The main purpose is to highlight relative advantages and disadvantages of each system and propose a methodologic approach for comparisons. Twenty clinical plans were inversely planned with step-and-shoot intensity-modulated radiotherapy (IMRT) each using 9 to 11 beams, referred to as IMRT_P. The prescription dose was 24 Gy in 2 fractions, and the plans were generated following our institutional protocol using the Pinnacle3 v9.2. (Source: Medical Dosimetry)
Source: Medical Dosimetry - August 1, 2019 Category: Radiology Authors: Young Kyung Lee, Iram Munawar, Shahram Mashouf, Arjun Sahgal, Mark Ruschin Source Type: research

The effects of the orthopedic metal artifact reduction (O-MAR) algorithm on contouring and dosimetry of head and neck radiotherapy patients
Metallic objects, such as dental fillings, cause artifacts in computed tomography (CT) scans. We quantify the contouring and dosimetric effects of Orthopedic Metal Artifact Reduction (O-MAR), in head and neck radiotherapy.The ease of organ contouring was assessed by having a radiation oncologist identify the CT data set with or without O-MAR for each of 28 patients that was easier to contour. The effect on contouring was quantified further by having the physician recontour parotid glands, previously drawn by him on the O-MAR scans, on uncorrected scans, and calculating the Dice coefficent (a measure of overlap) for the con...
Source: Medical Dosimetry - July 30, 2019 Category: Radiology Authors: Jussi Sillanpaa, Michael Lovelock, Boris Mueller Source Type: research

Using a whiteboard web application for tracking treatment workflow metrics for dosimetrists and physicians
We present a framework for collecting data which elucidates detailed clinical flow timelines for different treatment sites, modalities, planners, and physicians in radiotherapy treatments. A web based tool, the Whiteboard, was developed which allows communication between the physicians and staff about the current state of the radiotherapy treatment plan and provides detailed time data for each stage of the patient's journey from simulation to treatment. Detailed timestamped data was collected over a period of 6 years which included 22 discrete steps of the treatment planning process. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 29, 2019 Category: Radiology Authors: Rex A. Cardan, Elizabeth L. Covington, John B. Fiveash, Richard A. Popple Source Type: research

Automatic segmentation for adaptive planning in nasopharyngeal carcinoma IMRT: Time, geometrical, and dosimetric analysis
The aim of this study was to quantify the geometrical differences between manual contours and autocontours, the dosimetric impacts, and the time gain of using autosegmentation in adaptive nasopharyngeal carcinoma (NPC) intensity-modulated radiotherapy (IMRT) for a commercial system. A total of 20 consecutive Stages I to III NPC patients who had undergone adaptive radiation therapy (ART) re planning for IMRT treatment were retrospectively studied. Manually delineated organs at risks (OARs) on the replanning computed tomography (CT) were compared with the autocontours generated by VelocityAI using deformable registration fro...
Source: Medical Dosimetry - July 23, 2019 Category: Radiology Authors: Nelson Tsz Cheong Fung, Wai Man Hung, Chun Kin Sze, Michael Chi Hang Lee, Wai Tong Ng Source Type: research

Analyzation of the local confidence limits for IMRT and VMAT based on AAPM TG119 report
The aim of this study was to generate a local confidence limit (CL) for intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) techniques for Clinac IX linear accelerator using the American Association of Physicists in Medicine (AAPM) Task Group (TG119) protocol. The results were compared with the published studies to test the capability and quality of the VMAT technique in our clinic. We used TG119 cases to create plans for IMRT and VMAT in Eclipse Treatment Planning System for Clinac IX using 6 MV and 10 MV photons. (Source: Medical Dosimetry)
Source: Medical Dosimetry - July 8, 2019 Category: Radiology Authors: Jun Zhang, Dazhen Jiang, Hui Liu, Jiuling Shen, Dajiang Wang, Cheng Chen, Conghua Xie, Zhen Cao Source Type: research

An evaluation of adaptive planning by assessing the dosimetric impact of weight loss throughout the course of radiotherapy in bilateral treatment of head and neck cancer patients
The purpose of this study was to investigate the dosimetric impact of weight loss in head and neck (H&N) patients and examine the effectiveness of adaptive planning. Data was collected from 22 H&N cancer patients who experienced weight loss during their course of radiotherapy. The robustness of Intensity Modulated Radiation Therapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) treatment plans were compared including the potential need for replanning. The dosimetric impact of weight loss was evaluated by calculating a verification plan for each patient on an assessment CT scan taken during the course of treatme...
Source: Medical Dosimetry - June 17, 2019 Category: Radiology Authors: Zachary Stauch, Wesley Zoller, Kayla Tedrick, Steve Walston, Daniel Christ, Ashley Hunzeker, Nishele Lenards, Lee Culp, Mauricio E. Gamez, Dukagjin Blakaj Source Type: research

Late-course accelerated hyperfractionated intensity-modulated radiotherapy for nasopharyngeal adenoid cystic carcinoma: A case report
We report a case of T3N0 NACC with a positive resection margin treated with postoperative adjuvant radiotherapy. MRI reexamination indicated suspected tumor progression during the course of radiotherapy. In order to improve local control, late-course accelerated hyperfractionated intensity-modulated radiotherapy (LCAF-IMRT) was performed to escalate total dose, which achieved good local control with no significant late toxicity. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 15, 2019 Category: Radiology Authors: Dehuan Xie, Aoqiang Chen, Shaowen Lv, Huizhong Zhang, Xuekui Liu, Yong Su Source Type: research

Evaluation of a new hybrid VMAT-IMRT multi-criteria optimization plan generation algorithm
To evaluate the Varian ‘Fast hybrid multi-criteria optimization (MCO) volumetric modulated arc therapy (VMAT)’ (H-VMAT) tool for both its dosimetric accuracy and calculation time. This is a new function within V15.6 of the Varian Eclipse treatment planning system that allows VMAT optimization and dose calculation usin g the graphical processing unit (GPU). In versions prior to V15.6 VMAT MCO calculations were only possible using central processing unit (CPU) not GPU. We termed this approach as native VMAT (N-VMAT). (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 10, 2019 Category: Radiology Authors: Myles Spalding, Anthony Walsh, Hayley Clarke, Trent Aland Source Type: research

Tomotherapy as a neoadjuvant treatment for locally advanced esophageal cancer might increase bone marrow toxicity in comparison with intensity-modulated radiotherapy and volumetric-modulated arc therapy
This study compares dosimetric parameters in these following 3 neoadjuvant chemoradiotherapy (NCRT) methods in treating locally advanced esophagus cancer: helical tomotherapy (TOMO), volumetric modulated arc therapy (VMAT), and intensity-modulated radiotherapy (IMRT). It is aimed to ascertain the efficient technique that kept high target coverage and availed the dose sparing of bone marrow (BM). This research collected data on 11 patients from October 2014 to June 2017 who received NCRT for pathologically confirmed esophageal cancer. (Source: Medical Dosimetry)
Source: Medical Dosimetry - June 5, 2019 Category: Radiology Authors: Yulong Wang, Qin Xiao, Biao Zeng, Qianxi Ni, Xuewen Liu, Xiaoyang Liu, Lamei Tian, Cai Sheng, Lijuan Peng, Hui Wang Source Type: research

Assessment of deep inspiration breath hold technique setup reproducibility using mega voltage imaging for left breast cancer radiation therapy –integrated network study
We evaluated daily setup reproducibility of deep inspiration breath hold (DIBH) using mega voltage (MV) imaging for left breast cancer radiation therapy. Analysis of 109 left breast cancer patients across UPMC Hillman Cancer Center network treated using DIBH technique with daily MV imaging was done. Patient characteristics, MV imaging procedure used and inter-fraction directional shifts were collected. For the statistical analyses, we separated all patients into 2 groups in each of the following 3 categories; (1) obese (BMI ≥ 30) vs nonobese, (2) mastectomy vs lumpectomy, (3) internal mammary node (IMN) treatment vs no ...
Source: Medical Dosimetry - May 30, 2019 Category: Radiology Authors: HaYeon Kim, M. Saiful Huq, Dwight E. Heron, Ron Lalonde, Christopher J. Houser, Colin E. Champ, Sushil Beriwal Source Type: research

Evaluation of the robustness of 3-dimensional conformal technique with MLC position control into the planning target volume in stereotactic body radiotherapy for lung cancer
The purpose of this study was to evaluate the robustness of 3-dimensional conformal technique with MLC position control into the planning target volume (PTV) in stereotactic body radiotherapy for lung cancer. Two techniques using fixed beams were compared; one technique involved setting the MLC position outside the PTV and was referred to as Plan “O.” Another technique involved setting the MLC position inside the PTV and was referred to as Plan “I.” Two tumor motions were simulated: (1) tumor motion on the internal target volume (ITV) boundary and (2) tumor motion on the PTV boundary. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 25, 2019 Category: Radiology Authors: Masahide Saito, Naoki Sano, Kengo Kuriyama, Takafumi Komiyama, Kan Marino, Shinichi Aoki, Yoshiyasu Maehata, Ryo Saito, Hidekazu Suzuki, Yuki Shibata, Koji Ueda, Hiroshi Onishi Source Type: research

Postmastectomy radiotherapy for left-sided breast cancer patients: Comparison of advanced techniques
Postmastectomy radiotherapy (PMRT) has been shown to improve the overall survival for invasive breast cancer patients, and many advanced radiotherapy technologies were adopted for PMRT. The purpose of our study is to compare various advanced PMRT techniques including fixed-beam intensity-modulated radiotherapy (IMRT), non-coplanar volumetric modulated arc therapy (NC-VMAT), multiple arc VMAT (MA-VMAT), and tomotherapy (TOMO). Results of standard VMAT and mixed beam therapy that were published by our group previously were also included in the plan comparisons. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 23, 2019 Category: Radiology Authors: Yibo Xie, Daniel Bourgeois, Beibei Guo, Rui Zhang Source Type: research

Multicriteria optimization: Site-specific class solutions for VMAT plans
Multicriteria optimization (MCO), a novel commercially available optimization method for IMRT and VMAT has the potential to improve treatment planning techniques and workflows. MCO allows planners and physicians to assess in real time the impact and tradeoffs between all clinical goals and organ constraints. We investigate the feasibility of a universal set of objectives and constraints for VMAT plans in different anatomical sites and the impact of involving the Physician in the navigation of the generated Pareto plans. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 15, 2019 Category: Radiology Authors: Mariana Guerrero, Zachary Fellows, Pranshu Mohindra, Shahed Badiyan, Narottam Lamichhane, James W. Snider, Shifeng Chen Source Type: research

Dosimetric and radiobiological comparison of prostate VMAT plans optimized using the photon and progressive resolution algorithm
This study compared the dosimetric and radiobiological parameters of prostate volumetric modulated arc therapy (VMAT) plans using different prescriptions optimized by the photon optimization (PO) and progressive resolution optimization (PRO) algorithm. A total of 20 prostate patients were selected retrospectively and divided into 2 groups of VMAT plans using prescriptions of 60 Gy/20 fx and 79 Gy/38 fx. Inverse treatment planning optimized by the PO and PRO algorithm based on the dual-arc technique was carried out by the Eclipse treatment planning system. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 15, 2019 Category: Radiology Authors: James C.L. Chow, Runqing Jiang, Lu Xu Source Type: research

Dosimetric considerations when utilizing Venezia, Capri, Rotte double tandem, and tandem and ring with interstitial needles for the treatment of gynecological cancers with high dose rate brachytherapy
This work evaluated the difference in dosimetry of high dose rate (HDR) brachytherapy treatments between plans using advanced multichannel applicators and simplified base versions. Eighteen HDR patients treated using Interstitial Ring CT/MR Applicator Set (Elekta Brachytherapy, Netherlands) (TRN) (21 plans), CapriTM Applicator Set (Varian Medical Systems, Inc., Palo Alto, CA) (CC) (19 plans), Rotte Endometrial Applicator Set (Elekta Brachytherapy, Netherlands) (RDT) (18 plans), and the Advanced Gynecological Applicator Venezia (Vz) (Elekta Brachytherapy, Netherlands) (6 plans) were retrospectively reviewed. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 14, 2019 Category: Radiology Authors: Erich Schnell, Spencer Thompson, Salahuddin Ahmad, Terence S. Herman, Tania De La Fuente Herman Source Type: research

Variation of V105% between pre- and postmerged subfields in field-in-field hypofractionated breast radiotherapy plans
Hypofractionated whole-breast irradiation has emerged as a viable alternative to conventional fractionation. In the field-in-field forward planning technique, a merged plan with 2 to 4 segmental fields is the final plan delivered to the machine. As per the ASTRO guidelines for the hypofractionation regimen, the volume of breast tissue receiving V105% of the prescription dose should be less than 200 cc. However, we have noticed substantial changes to this volume (change in V105% between −55 cc and + 47.1 cc) after merging the subfields. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 14, 2019 Category: Radiology Authors: Abhishek Dwivedi, Therese McGarry, Laura Bond, Joel K. Braver, Nrusingh C. Biswal Source Type: research

Dosimetric comparison of short and full arc in spinal PTV in volumetric-modulated arc therapy-based craniospinal irradiation
This study was aimed to do a dosimetric comparison between the large and shorter spinal arc for CSI. For a cohort of 10 patients, 2 VMAT CSI plans were created for each patient, one using the conventional full 360° arc (VMAT_FA) for the spine and the other using 100° posterior arc (VM AT_PA) for 23.4 Gy and 35 Gy prescriptions. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 15, 2019 Category: Radiology Authors: Biplab Sarkar, Anusheel Munshi, Tharmarnadar Ganesh, Arjunan Manikandan, Bidhu K. Mohanti Source Type: research

Comparison of 2 methods for prediction of liver dosimetric indices in hepatocellular cancer IMRT planning
To evaluate the performance of 2 methods predicting liver dosimetric indices for hepatocellular cancer patients treated with intensity modulated radiation therapy (IMRT). Two predicting methods were implemented to build correlation between geometric and dosimetric information of hepatocellular cancer IMRT plans. One method used Principle Component Analysis method to simplify information and Support Vector Machine (SVM) regression method to build correlation. The other method used a simple linear function to map volumes of certain regions to dosimetic indices. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 12, 2019 Category: Radiology Authors: Weijie Cui, Weihu Wang, Zhihui Hu, Jianrong Dai, Yexiong Li Source Type: research

Dominant intraprostatic lesion boosting in sexual-sparing radiotherapy of prostate cancer: A planning feasibility study
Radical radiotherapy of prostate cancer requires a relatively high dose to achieve an optimal tumor control probability and a reduced dose to the critical structures related to the sexual function (S_OARs) in order to avoid erectile dysfunction. The aim of this study was to perform a planning feasibility analysis of a 3-level dose prescription with Simultaneous Integrated Boost (SIB) on the dominant intraprostatic lesion (DIL) and with S_OARs sparing. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 4, 2019 Category: Radiology Authors: Selena Ciabatti, Maria Ntreta, Milly Buwenge, Caterina Gaudiano, Elisa Sessagesimi, Fabrizio Romani, Anna L. Angelini, Silvia Cammelli, Gabriella Macchia, Francesco Deodato, Alice Zamagni, Rita Golfieri, Alessio G. Morganti, Savino Cilla Source Type: research

Dosimetric characterization of a rigid, surface-contour-specific thermoplastic bolus material
A dosimetric analysis of a commercially available thermoplastic sheet bolus, Klarity EZ BolusTM, was completed. Attenuation characteristics were evaluated using different configurations of a rectilinear water-mimicking plastic phantom irradiated by a high-energy linear accelerator using three photon energies, five electron energies. These results were compared with data obtained during the linear accelerator commissioning process to determine depths of water that attenuated beams similarly. CT scans of the flat, unmolded sheet bolus, as well as of the bolus molded to a cylindrical phantom, were analyzed. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 2, 2019 Category: Radiology Authors: Jessica M. Fagerstrom Source Type: research

Automatizing a nonscripting TPS for optimizing clinical workflow and reoptimizing IMRT/VMAT plans
The purpose of this study was to design a toolkit that interacts with the Monaco (Elekta AB, Stockholm, Sweden) treatment planning system (TPS) for optimization of intensity-modulated radiation therapy and volumetric-modulated arc therapy without the need for a dedicated application programming interface. Successful inverse planning of radiotherapeutic treatment depends on the tweaking of many parameters; a tool was thus needed to explore these parameters more exhaustively without significantly increasing planning time. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 2, 2019 Category: Radiology Authors: Rafael Ayala, Gema Ruiz, Teresa Valdivielso Source Type: research

In reply to Letter to the Editor titled: “Use of electronic portal images to evaluate setup error and intrafraction motion during free-breathing breast intensity-modulated radiotherapy (IMRT) treatment: Common mistake in reliability analysis”
We appreciate having critical comments about our published paper. The commands described title of mistake in reliability analysis and inappropriate statistical method that was not acceptable. In the letter to editor, the author proposed Intraclass correlation coefficient and Bland –Altman plot to access inter-rating reliability. Actually, we used person correlation to evaluate distribution of vectors not for assessment of interrater reliability.1 (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 1, 2019 Category: Radiology Authors: Jing-Min Hwang, Chiou-Shiung Chang Tags: Letter to the Editor Source Type: research

Dosimetric study on learning-based cone-beam CT correction in adaptive radiation therapy
In this study, we aim to investigate the dosimetric accuracy of our corrected CBCT (CCBCT) in brain stereotactic radiosurgery (SRS) and pelvic radiotherapy. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 1, 2019 Category: Radiology Authors: Tonghe Wang, Yang Lei, Nivedh Manohar, Sibo Tian, Ashesh B. Jani, Hui-Kuo Shu, Kristin Higgins, Anees Dhabaan, Pretesh Patel, Xiangyang Tang, Tian Liu, Walter J. Curran, Xiaofeng Yang Source Type: research

Dosimetric comparison of intensity-modulated radiation therapy for early-stage glottic cancers with and without the air cavity in the planning target volume
For early-stage glottic cancers, intensity-modulated radiation therapy (IMRT) has been shown to have comparable local control to 3D-conformal radiotherapy with the advantage of decreased dose to the carotid arteries. The planning target volume (PTV) for early glottic cancers typically includes the entire larynx, plus a 3 to 5 mm uniform margin. The air cavity within the larynx creates a challenge for the inverse optimization process as the software attempts to “build up” dose within the air. This unnecessary attempt at dose build-up in air can lead to hot spots within the rest of the PTV and surrounding soft ti...
Source: Medical Dosimetry - March 28, 2019 Category: Radiology Authors: David Asher, William Amestoy, Matthew T. Studenski, Stuart E. Samuels, Matthew C. Abramowitz, Laura M. Freedman, Nagy Elsayyad, Michael A. Samuels Source Type: research

Feasibility of spine stereotactic body radiotherapy for patients with large tumors in multiple vertebrae undergoing re-irradiation: Dosimetric challenge using 3 different beam delivery techniques
The objective of the present study was to report whether the adequate spine stereotactic body radiotherapy (SBRT) plans were generated with feasible treatment duration for patients with large vertebral metastases undergoing re-irradiation. For 5 cases, the re-irradiation plans using static-field intensity-modulated radiation therapy (SIMRT), volumetric-modulated arc therapy (VMAT), and CyberKnife with a total prescribed dose (PD) of 24 Gy applied in 2 fractions were generated. A minimum dose to 95% of the evaluated planning target volume (PTVevl) that was>70% of PD (D95> 70% PD) was defined as minimum criterion. (Sou...
Source: Medical Dosimetry - March 28, 2019 Category: Radiology Authors: Tomohisa Furuya, Jun H. Phua, Kei Ito, Katsuyuki Karasawa Source Type: research

Individual Field Simultaneous Optimization (IFSO) in spot scanning proton therapy of head and neck cancers
In this study we report the clinical utilization of a novel and robust scanning proton beam therapy treatment planning method called Individual Field Simultaneous Optimization (IFSO) that incorporates the advantages of field patching technique integrated with simultaneous optimization of multiple fields. A treatment planning intercomparison between a conventional Intensity Modulated Proton Therapy Treatment Plan with single target volume vs a split target volume utilizing IFSO method demonstrates superiority of IFSO with regards to sparing of organs at risk and plan robustness. (Source: Medical Dosimetry)
Source: Medical Dosimetry - March 12, 2019 Category: Radiology Authors: Aman Anand, Martin Bues, Mauricio E. Gamez, Corbin Stefan, Samir H. Patel Source Type: research

Evaluation of the effectiveness of novel single-intervention adaptive radiotherapy strategies based on daily dose accumulation
This study focuses on the difference between planned dose and delivered dose and the possible effects of an efficient replanning strategy during the course of treatment. Six patients with H&N cancer treated by tomotherapy were retrospectively enrolled. Thirty daily dose distributions (DMVCT) were calculated on pretreatment megavoltage computed tomography (MVCT) scans. (Source: Medical Dosimetry)
Source: Medical Dosimetry - March 12, 2019 Category: Radiology Authors: Alberto Ciarmatori, Nicola Maffei, Grazia Maria Mistretta, Paola Ceroni, Annalisa Bernabei, Bruno Meduri, Elisa D'Angelo, Alessio Bruni, Patrizia Giacobazzi, Frank Lohr, Gabriele Guidi Source Type: research

Image-guidance technique comparison on respiratory reproducibility and dose indexes for stereotactic body radiotherapy in lung tumor ☆
Recently, image-guided radiation therapy (IGRT) has been widely used in clinical practices.1,2 This is because highly accurate localization and positioning for are required for target to facilitate high-accuracy external radiotherapy such as stereotactic body radiotherapy (SBRT).3,4 In addition, organ motion should also be considered during SBRT in lung tumors. IGRT can be used to confirm and correct the target position prior to irradiation, and thus it can reduce the setup error of the target. It is recommended that the positioning accuracy of the target during irradiation should have an error of ≤5 mm in fractionated ...
Source: Medical Dosimetry - March 8, 2019 Category: Radiology Authors: Ryuji Kanzaki, Fujio Araki, Shinji Kawamura Source Type: research

Evaluation of the use of abdominal compression of the lung in stereotactic radiation therapy
The goal of this retrospective study was to determine the benefit in using abdominal compression to reduce tumor motion for patients treated with lung stereotactic body radiotherapy. Forty-four lung lesions (n  = 44) from 37 patients (N = 37) treated at the University of Toledo's Dana Cancer Center were assessed by determining the overall tumor displacement along with possible surrogates such as change in tidal volume and diaphragm displacement, with and without abdominal compression. Measurements of lung capacity were acquired from the 4DCT at maximum and minimum respiration in order to determine the tidal volume,...
Source: Medical Dosimetry - March 6, 2019 Category: Radiology Authors: Saba Javadi, Jacob Eckstein, Vincent Ulizio, Russell Palm, Krishna Reddy, David Pearson Source Type: research

Radiation Dose in the Uterine Perforation by Tandem in 3-Dimensional Cervical Cancer Brachytherapy
Cervical cancer patients may sometimes experience different types of uterine perforation by a tandem during brachytherapy. The purpose of this study was to address possibly different management strategies regarding different tandem positions from a dosimetry aspect by evaluating radiation doses delivered to organs-at-risk (OAR) in order to help medical professionals handle different types of uterine perforation. Images and dosimetry data in cervical cancer brachytherapy with uterine perforation were reviewed. (Source: Medical Dosimetry)
Source: Medical Dosimetry - March 4, 2019 Category: Radiology Authors: Yu-Lun Tsai, Pei-Chieh Yu, Hsin-Hua Nien, Shih-Yu Sung, Yi-Hsuan Kuan, Ching-Jung Wu Source Type: research

Automated noncoplanar treatment planning strategy in stereotactic radiosurgery of multiple cranial metastases: HyperArc and CyberKnife dose distributions
The purpose of this study was to evaluate and compare the dosimetric effects of HyperArc-based stereotactic radiosurgery (SRS) and a robotic radiosurgery system-based planning using CyberKnife for multiple cranial metastases. In total, 11 cancer patients with multiple cranial metastases (3 to 5 tumors) treated with CyberKnife were examined. These patients were replanned using HyperArc (Varian Medical Systems, Palo Alto, USA). HyperArc plan were designed using 4 noncoplanar arc single-isocenter VMAT in 6 MV flattening filter free mode for simulated delivery with the True beam STx (Varian). (Source: Medical Dosimetry)
Source: Medical Dosimetry - March 1, 2019 Category: Radiology Authors: Noriyuki Kadoya, Yoshitomo Abe, Tomohiro Kajikawa, Kengo Ito, Takaya Yamamoto, Rei Umezawa, Takahito Chiba, Yoshiyuki Katsuta, Yoshiki Takayama, Takahiro Kato, Yasuhiro Kikuchi, Keiichi Jingu Source Type: research

Use of electronic portal images to evaluate setup error and intrafraction motion during free-breathing breast IMRT treatment: Common mistake in reliability analysis
We were interested to read the paper by Hwang, and colleagues published in Medical Dosimetry Journal in 2018. The purpose of the study was to test the effectiveness of an EPID device for collecting portal images and monitoring setup error and intrafractional motion during intensity-modulated beam delivery. Authors reported that Pearson's correlations and Cohen's kappa statistics were calculated as part of the researchers ’ evaluation of the agreement between the 2 therapists.1 (Source: Medical Dosimetry)
Source: Medical Dosimetry - March 1, 2019 Category: Radiology Authors: Seyyed Mohammad Tabatabaei, Meisam Shahsavari Tags: Letter to the Editor Source Type: research

Performance evaluation of the X-sight spine tracking system for abdominal tumors distal to spine: A 2D dosimetric analysis
The X-sight spine tracking system was integrated with Cyberknife unit to deliver radiosurgery treatments for spinal tumors without fiducial placement. However the tracking system can also be used for the treatment of abdominal tumors located in a certain distance from the spine. The aim of our study is to evaluate the tracking performance of the X-sight spine system for abdominal tumors distal to spine based on the 3 factors: tumor distance from the reference vertebra, the angle of tumor with the vertebra, and the amplitude of tumor motion due to respiration. (Source: Medical Dosimetry)
Source: Medical Dosimetry - February 22, 2019 Category: Radiology Authors: Selami Eken, Faruk Zorlu, Mete Yeginer, Gokhan Ozyigit Source Type: research

Monte Carlo dose verification for a single-isocenter VMAT plan in multiple brain metastases
The purpose of this study was to verify the accuracy of dose calculation algorithms of a treatment planning system for a single-isocenter volumetric modulated arc therapy (VMAT) plan in multiple brain metastases, by comparing the dose distributions of treatment planning system with those of Monte Carlo (MC) simulations. We used a multitarget phantom containing 9 acrylic balls with a diameter of 15.9 mm inside a Lucy phantom measuring 17  × 17 × 17 cm3. Seven VMAT plans were created using the multitarget phantom: 1 multitarget plan (MTP) and 6 single target plans (STP). (Source: Medical Dosimetry)
Source: Medical Dosimetry - February 6, 2019 Category: Radiology Authors: Kento Hoshida, Fujio Araki, Takeshi Ohno, Hirofumi Tominaga, Kazuki Komatsu, Kentaro Tamura Source Type: research

Dose evaluation of MRI-based synthetic CT generated using a machine learning method for prostate cancer radiotherapy
In this study, we aim to investigate the accuracy of dose calculation in prostate cancer radiotherapy using SCTs generated from MRIs using our learning-based method. We retrospectively investigated a total of 17 treatment plans from 10 patients, each having both planning CTs (pCT) and MRIs acquired before treatment. (Source: Medical Dosimetry)
Source: Medical Dosimetry - February 1, 2019 Category: Radiology Authors: Ghazal Shafai-Erfani, Tonghe Wang, Yang Lei, Sibo Tian, Pretesh Patel, Ashesh B. Jani, Walter J. Curran, Tian Liu, Xiaofeng Yang Source Type: research

End-to-end testing of automatic plan optimization using RayStation scripting for hypofractionated multimetastatic brain stereotactic radiosurgery
For external beam stereotactic radiosurgery of multiple brain metastatic lesions, it is difficult to select optimal treatment isocenters because the orientation and volume of each planning target volume (PTV) and its proximity to critical structures are unique for each patient. The RayStation treatment planning system offers Python-based scripting to optimize the placement of the treatment isocenter by comparing scenario-based plans. This can improve the plan quality by reducing the dose to the normal brain and increasing planning efficiency. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 14, 2019 Category: Radiology Authors: Eun Young Han, Gwe-Ya Kim, Neal Rebueno, Debra N. Yeboa, Tina M. Briere Source Type: research

Dosimetric comparison of helical tomotherapy and VMAT for anal cancer: A single institutional experience
To compare the dosimetric results of helical tomotherapy (HT) and volumetric arc therapy (VMAT) in the treatment of anal cancer. Plans were created for 20 (n  = 20) patients treated for anal cancer using HT and 2 arc VMAT. Dosimetric comparison was assessed for doses to targets and organs at risk (small bowel, bladder, external genitalia, and femoral heads). Delivery time and dosimetric verification results were also compared. HT showed a higher V95% for both primary and nodal targets (V95% increase by 0.5% to 1.3%; p = ≤0.05). (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 11, 2019 Category: Radiology Authors: Ian Gleeson, Christopher Rose, Joshua Spurrell Source Type: research

Evaluation of the correlation between prostatic displacement and rectal deformation using the Dice similarity coefficient of the rectum
To estimate the relationship between the three-dimensional (3D) displacement error of the prostate and rectal deformation for reduction of deviation between the planned and treatment dose, using multiple acquisition planning CT (MPCT) and the Dice similarity coefficient (DSC) for rectal deformation for treatment of patients with prostate cancer. The 3D displacement error between the pelvic bone and a matching fiducial marker was calculated using MPCT in 24 patients who underwent prostate volumetric-modulated arc therapy for prostate cancer. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 11, 2019 Category: Radiology Authors: Yoshinori Tanabe, Takayuki Ishida, Hidetoshi Eto, Tatsuhiro Sera, Yuki Emoto Source Type: research

Feasibility study of using flattening-filter-free photon beams to deliver conventional flat beams
In this study, we concentrate on investigating the feasibility of using FFF beams to deliver conventional flat beams, since completely getting rid of the flattening-filter module from the gantry head can not only simplify the gantry design but also decrease the workload on machine maintenance and quality assurance. Two intensity modulated radiotherapy techniques, step-and-shoot (S&S) and sliding window (SW), were used to generate flat beam profiles for 6 regular-shaped beams and 3 clinical beams while operating in FFF mode. (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 7, 2019 Category: Radiology Authors: Nicholas J. Potter, Sharon Lebron, Jonathan G. Li, Chihray Liu, Bo Lu Source Type: research

Usefulness of EZFluence software for radiotherapy planning of breast cancer treatment
This study compared the EZFluence planning technique for irradiation of the breast with commonly used Field-in-Field (FiF) technique by analyzing the dose uniformity, the dose to the lung, heart, and other organs at risk, the total Monitor Unit (MU), and the time spent for planning. Two different 3-dimensional conformal dose plans were created for 20 breast cancer patients. Six patients were treated to a dose of 5000 cGy in 25 fractions and 14 were treated to a dose of 4256 cGy in 16 fractions. Average breast volume was 800 cc (range 128 to 1892 cc). (Source: Medical Dosimetry)
Source: Medical Dosimetry - January 2, 2019 Category: Radiology Authors: Todd Yoder, An Ting Hsia, Zhigang Xu, Alexander Stessin, Samuel Ryu Source Type: research

Appropriate treatment planning method for field joint dose in total body irradiation using helical tomotherapy
Total body irradiation (TBI) using helical tomotherapy (HT) has advantages over the standard linear accelerator-based approach to the conditioning regimen for hematopoietic cell transplantation. However, the radiation field has to be divided into two independent irradiation plans to deliver a homogeneous dose to the whole body. A clinical target volume near the skin increases the skin surface dose; therefore, high- or low-dose regions arise depending on the set-up position accuracy because the two radiation fields are somewhat overlapped or separated. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 28, 2018 Category: Radiology Authors: Keisuke Usui, Akira Isobe, Naoya Hara, Naoto Shikama, Keisuke Sasai, Koichi Ogawa Source Type: research

Dosimetric comparison of vaginal vault brachytherapy vs applicator-guided stereotactic body radiotherapy with volumetric modulated arc therapy and helical tomotherapy for endometrium cancer patients
We performed this dosimetric study to compare a nonstandard volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT) techniques with high-dose rate (HDR) brachytherapy (BRT) plan of vaginal vault in patients with postoperative endometrial cancer (EC). Twelve postoperative patients with early stage EC were included in this study. Three plans were performed for each patient; dosimetric and radiobiological comparisons were made using dose-volume histograms and equivalent dose for determining the planning target volume (PTV) coverages in brachytherapy and external beam radiotherapy, and organs-at-risk (OARs) doses ...
Source: Medical Dosimetry - December 11, 2018 Category: Radiology Authors: Berna Akkus Yildirim, Yemliha Dolek, Ozan Cem Guler, Gungor Arslan, Cem Onal Source Type: research

A statistics-based model for prediction of achievability of the planning criteria for IMRT planning
The purpose of this study is to develop and evaluate a statistics-based model to predict the achievability of the planning criteria for intensity-modulated radiation therapy planning. A statistics-based model was proposed to predict the achievability of the planning criteria based on the structure set. A retrospective study was performed to validate the proposed model. A total of 160 prostate cases and 134 nasopharynx (NP) cases were used as the training set to build the model while 200 cases for each treatment site were used to validate the proposed model. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 5, 2018 Category: Radiology Authors: King Hang Wicger Wong, Hing Tong Lucullus Leung, Lai Wan Dora Kwong Source Type: research

Effect of arc length on skin dose from hypofractionated volumetric modulated arc radiotherapy treatments of the lung and spine
Due to large doses per fraction, stereotactic ablative radiotherapy of lung or spine can lead to skin tissue toxicity, the amount of which depends on a variety of factors such as target location, beam geometry, and immobilization. The effect of arc length on spreading out entrance and exit doses and the corresponding predictions of skin reactions has not yet been studied for stereotactic body radiotherapy volumetric modulated arc therapy (VMAT) treatments. 58 clinically relevant VMAT stereotactic body radiotherapy spine and lung plans were created for an anthropomorphic phantom utilizing a range of target locations, beam g...
Source: Medical Dosimetry - December 4, 2018 Category: Radiology Authors: James Rijken, Tanya Kairn, Scott Crowe, Jamie Trapp Source Type: research

Predictive performance of an OVH-based treatment planning quality assurance model for prostate VMAT: Assessing dependence on training cohort size and composition
In this study, a treatment planning quality assurance model for prostate cancer patients treated with volumetric modulated arc therapy was developed using the concept of the overlap volume histogram for geometric comparison to the training cohort. The model was developed on the publically available Erasmus iCycle dataset in order to remove the effect of plan quality/inter-planner variability on the model's predictive capabilities. (Source: Medical Dosimetry)
Source: Medical Dosimetry - December 3, 2018 Category: Radiology Authors: Alex Burton, Craig Norvill, Martin A Ebert Source Type: research

IMRT planning parameter optimization for spine stereotactic radiosurgery
Spine stereotactic radiosurgery (SSRS) is a noninvasive treatment for metastatic spine lesions. MD Anderson Cancer Center reports a quality assurance (QA) failure rate approaching 15% for SSRS cases, which we hypothesized is due to difficulties in accurately calculating dose resulting from a large number of small-area segments. Clinical plans typically use 9 beams with an average of 10 segments per beam and minimum segment area of 2-3 cm2. The purpose of this study was to identify a set of intensity-modulated radiation therapy (IMRT) planning parameters that attempts to optimize the balance among QA passing rate, plan qual...
Source: Medical Dosimetry - December 1, 2018 Category: Radiology Authors: Gabriel B. Ayala, Kieu A. Doan, Hie Ji Ko, Peter K. Park, Edwin D. Santiago, Shirly J. Kuruvila, Amol J. Ghia, Tina M. Briere, Zhifei Wen Source Type: research

Selecting noncoplanar beam directions in a patient coordinate system for radiotherapy planning
To introduce a beam angle selection method based on the patient coordinate system for treatment planning of noncoplanar intensity-modulated radiation therapy (IMRT). Traditionally, in radiotherapy planning, beam directions are selected in the machine coordinate system. A noncoplanar beam direction is established through a treatment table rotation followed by a gantry rotation. However, visualizing the beam direction relative to the patient is difficult. The suggestion here is to describe the beam direction in the patient coordinate system. (Source: Medical Dosimetry)
Source: Medical Dosimetry - November 23, 2018 Category: Radiology Authors: Chuanmeng Niu, Minghui Li, Hui Yan, Chenlei Guo, Jianrong Dai Source Type: research

Dependence of volume dose indices on dose calculation algorithms for VMAT-SBRT plans for peripheral lung tumor
The purpose of this study was to investigate the dependence of volume dose indices on dose calculation algorithms for volumetric modulated arc therapy (VMAT) for stereotactic body radiotherapy (SBRT) plans to treat peripheral lung tumors by comparing them with those of Monte Carlo (MC) calculations. VMAT-SBRT plans for peripheral lung tumors were created using the Eclipse treatment planning system (TPS) for 24 patients with nonsmall cell lung cancer. VMAT dose distributions for gross tumor volume (GTV), internal target volume (ITV), and planning target volume (PTV) were calculated using the analytical anisotropic algorithm...
Source: Medical Dosimetry - November 16, 2018 Category: Radiology Authors: Takanori Matsuoka, Fujio Araki, Takeshi Ohno, Junichi Sakata, Hirofumi Tominaga Source Type: research